A simultaneous generalization of independence and disjointness in boolean algebras

We give a definition of some classes of boolean algebras generalizing free boolean algebras; they satisfy a universal property that certain functions extend to homomorphisms. We give a combinatorial property of generating sets of these algebras, which we call n-independent. The properties of these classes (n-free and omega-free boolean algebras) are investigated. These include connections to hypergraph theory and cardinal invariants on these algebras. Related cardinal functions, $n$Ind, which is the supremum of the cardinalities of n-independent subsets; i_n, the minimum size of a maximal n-independent subset; and i_omega, the minimum size of an omega-independent subset, are introduced and investigated. The values of i_n and i_omega on P(omega)/fin are shown to be independent of ZFC.Comment: Sumbitted to Orde

The Migdal Effect and Photon Bremsstrahlung in effective field theories of dark matter direct detection and coherent elastic neutrino-nucleus scattering

Dark matter direct detection experiments have limited sensitivity to light dark matter (below a few GeV), due to the challenges of lowering energy thresholds for the detection of nuclear recoil to below $\mathcal{O}(\mathrm{keV})$. While impressive progress has been made on this front, light dark matter remains the least constrained region of dark-matter parameter space. It has been shown that both ionization and excitation due to the Migdal effect and coherently-emitted photon bremsstrahlung from the recoiling atom can provide observable channels for light dark matter that would otherwise have been missed owing to the resulting nuclear recoil falling below the detector threshold. In this paper we extend previous work by calculating the Migdal effect and photon bremmstrahlung rates for a general set of interaction types, including those that are momentum-independent or -dependent, spin-independent or -dependent, as well as examining the rates for a variety of target materials, allowing us to place new experimental limits on some of these interaction types. Additionally, we include a calculation of these effects induced by the coherent scattering on nuclei of solar or atmospheric neutrinos. We demonstrate that the Migdal effect dominates over the bremsstrahlung effect for all targets considered for interactions induced by either dark matter or neutrinos. This reduces photon bremsstrahlung to irrelevancy for future direct detection experiments.Comment: 17 pages, 6 figure

Why do Tornados and Hail Storms Rest on Weekends?

When anthropogenic aerosols over the eastern USA during summertime are at their weekly mid-week peak, tornado and hail storm activity there is also near its weekly maximum. The weekly cycle in storm activity is statistically significant and unlikely to be due to natural variability. The pattern of variability supports the hypothesis that air pollution aerosols invigorate deep convective clouds in a moist, unstable atmosphere, to the extent of inducing production of large hailstones and tornados. This is caused by the effect of aerosols on cloud-drop nucleation, making cloud drops smaller, delaying precipitation-forming processes and their evaporation, and hence affecting cloud dynamics

Prevalence of incidental breast cancer and precursor lesions in autopsy studies: A systematic review and meta-analysis

Abstract Background Autopsy studies demonstrate the prevalence pool of incidental breast cancer in the population, but estimates are uncertain due to small numbers in any primary study. We aimed to conduct a systematic review of autopsy studies to estimate the prevalence of incidental breast cancer and precursors. Methods Relevant articles were identified through searching PubMed and Embase from inception up to April 2016, and backward and forward citations. We included autopsy studies of women with no history of breast pathology, which included systematic histological examination of at least one breast, and which allowed calculation of the prevalence of incidental breast cancer or precursor lesions. Data were pooled using logistic regression models with random intercepts (non-linear mixed models). Results We included 13 studies from 1948 to 2010, contributing 2363 autopsies with 99 cases of incidental cancer or precursor lesions. More thorough histological examination (≥20 histological sections) was a strong predictor of incidental in-situ cancer and atypical hyperplasia (OR = 126·8 and 21·3 respectively, p < 0·001), but not invasive cancer (OR = 1·1, p = 0·75). The estimated mean prevalence of incidental cancer or precursor lesion was 19·5% (0·85% invasive cancer + 8·9% in-situ cancer + 9·8% atypical hyperplasia). Conclusion Our systematic review in ten countries over six decades found that incidental detection of cancer in situ and breast cancer precursors is common in women not known to have breast disease during life. The large prevalence pool of undetected cancer in-situ and atypical hyperplasia in these autopsy studies suggests screening programs should be cautious about introducing more sensitive tests that may increase detection of these lesions

Identification of senescence and death in Emiliania huxleyi and Thalassiosira pseudonana: Cell staining, chlorophyll alterations, and dimethylsulfoniopropionate (DMSP) metabolism

We measured membrane permeability, hydrolytic enzyme, and caspase-like activities using fluorescent cell stains to document changes caused by nutrient exhaustion in the coccolithophore Emiliania huxleyi and the diatom Thalassiosira pseudonana, during batch-culture nutrient limitation. We related these changes to cell death, pigment alteration, and concentrations of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) to assess the transformation of these compounds as cell physiological condition changes. E. huxleyi persisted for 1 month in stationary phase; in contrast, T. pseudonana cells rapidly declined within 10 d of nutrient depletion. T. pseudonana progressively lost membrane integrity and the ability to metabolize 5-chloromethylfluorescein diacetate (CMFDA; hydrolytic activity), whereas E. huxleyi developed two distinct CMFDA populations and retained membrane integrity (SYTOX Green). Caspase-like activity appeared higher in E. huxleyi than in T. pseudonana during the post-growth phase, despite a lack of apparent mortality and cell lysis. Photosynthetic pigment degradation and transformation occurred in both species after growth; chlorophyll a (Chl a) degradation was characterized by an increase in the ratio of methoxy Chl a : Chl a in T. pseudonana but not in E. huxleyi, and the increase in this ratio preceded loss of membrane integrity. Total DMSP declined in T. pseudonana during cell death and DMS increased. In contrast, and in the absence of cell death, total DMSP and DMS increased in E. huxleyi. Our data show a novel chlorophyll alteration product associated with T. pseudonana death, suggesting a promising approach to discriminate nonviable cells in nature

A Potential Role for the Interaction of Wolbachia Surface Proteins with the Brugia malayi Glycolytic Enzymes and Cytoskeleton in Maintenance of Endosymbiosis

The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis. © 2013 Melnikow et al

Lorentz transformations of open systems

We consider open dynamical systems, subject to external interventions by agents that are not completely described by the theory (classical or quantal). These interventions are localized in regions that are relatively spacelike. Under these circumstances, no relativistic transformation law exists that relates the descriptions of the physical system by observers in relative motion. Still, physical laws are the same in all Lorentz frames.Comment: Final version submitted to J. Mod. Opt. (Proc. of Gdansk conference

Proof of Kolmogorovian Censorship

Many argued (Accardi and Fedullo, Pitowsky) that Kolmogorov's axioms of classical probability theory are incompatible with quantum probabilities, and this is the reason for the violation of Bell's inequalities. Szab\'o showed that, in fact, these inequalities are not violated by the experimentally observed frequencies if we consider the real, ``effective'' frequencies. We prove in this work a theorem which generalizes this result: ``effective'' frequencies associated to quantum events always admit a Kolmogorovian representation, when these events are collected through different experimental set ups, the choice of which obeys a classical distribution.Comment: 19 pages, LaTe

High-Resolution Spectroscopy in Tr37: Gas Accretion Evolution in Evolved Dusty Disks

Using the Hectochelle multifiber spectrograph, we have obtained high-resolution (R~34,000) spectra in the Halpha region for a large number of stars in the 4 Myr-old cluster Tr 37, containing 146 previously known members and 26 newly identified ones. We present the Halpha line profiles of all members, compare them to our IR observations of dusty disks (2MASS/JHK + IRAC + MIPS 24 micron), use the radial velocities as a membership criterion, and calculate the rotational velocities. We find a good correlation between the accretion-broadened profiles and the presence of protoplanetary disks, noting that a small fraction of the accreting stars presents broad profiles with Halpha equivalent widths smaller than the canonical limit separating CTTS and WTTS. The number of strong accretors appears to be lower than in younger regions, and a large number of CTTS have very small accretion rates (dM/dt<10^{-9} Msun/yr). Taking into account that the spectral energy distributions are consistent with dust evolution (grain growth/settling) in the innermost disk, this suggests a parallel evolution of the dusty and gaseous components. We also observe that about half of the "transition objects" (stars with no IR excesses at wavelengths shorter than ~6 micron) do not show any signs of active accretion, whereas the other half is accreting with accretion rates <10^{-9} Msun/yr. These zero or very low accretion rates reveal important gas evolution and/or gas depletion in the innermost disk, which could be related to grain growth up to planetesimal or even planet sizes. Finally, we examine the rotational velocities of accreting and non accreting stars, finding no significant differences that could indicate disk locking at these ages.Comment: 51 pages, 13 (reduced resolution) figures, 2 tables. AJ in pres

Thomas G. Abernethy, Jamie L. Whitten, Arthur Winstead, John Bell Williams, William M. Colmer, James O. Eastland, John C. Stennis to President John F. Kennedy, 28 September 1962;

Press release dated 28 September 1962, re: letter from Thomas G. Abernethy, Jamie L. Whitten, Arthur Winstead, John Bell Williams, William M. Colmer, James O. Eastland, and John C. Stennis to Kennedy in regards to integration of the University of Mississippi by James Meredith.https://egrove.olemiss.edu/joecorr_d/1011/thumbnail.jp